Motoric Cognitive Risk and Incident Dementia in Older Adults

Key Points Question Is modified motoric cognitive risk (MCR) that incorporates the timed-up-and-go (TUG) and one-leg-standing (OLS) tests able to estimate the risk of incident dementia? Findings In this large, nationwide cohort study with 1 137 530 individuals aged 66 years, both the MCR-TUG and MCR-OLS groups exhibited an approximately 2-fold significantly higher risk of incident dementia than the non-MCR groups. The MCR group exhibited a higher cumulative incidence of dementia and significantly shorter follow-up period than those in non-MCR groups. Meaning The findings of this study suggest that modified MCR may be used as a practical screening tool for estimating dementia among individuals in their mid-60s.


Data sources
Data were obtained retrospectively from the Korean National Health Insurance (KNHI) database.As enrollment in the KNHI is mandatory in Korea, approximately 97% of the Korean population are subscribed, and the remaining 3% of individuals are covered through Medicaid. 1 Through the National Health Screening Program, Koreans receive regular health check-up from birth and every two years from the age of 20.In 2007, the National Screening Program for Transitional Ages (NSPTA) was launched as part of the national health examination to focus on pivotal life transition periods at the ages of 40 and 66. 2 The health screening performed in individuals aged 66 years includes additional components, such as physical and cognitive function assessment and osteoporosis screening beyond the standard checks. 2ince the KNHI acts as the single insurer in Korea and is responsible for all administrative processes and reimbursements related to medical service claims, the KNHI database contains health information and examination results for the entire population. 3hile collected for administrative purposes, the KNHI supports policy and academic research utilizing this information.The provision of this data requires official review and approval of research proposals, and Institutional Review Board (IRB) approval or exemption is mandatory.Since KNHI data provides only anonymized and de-identified information, the requirement for informed consent was waived. 1 Raw data cannot be exported and analysis is permitted only within specified rooms.In this study, the dataset was generated with the permission of the National Health Insurance Sharing Service (NHIS-2021-1-449).

Subjective cognitive decline (SCD) assessment
The pre-screening Korean Dementia Screening Questionnaire (KDSQ-P) 4 was implemented as part of the NSPTA as a preliminary survey for the KDSQ suitable for use exclusively in large group settings.The KDSQ-P is a self-reported questionnaire consisting of the following five questions: (1) Do you perceive your memory to be worse than that of your friends and colleagues?; (2) Do you believe your memory has regressed compared to its state a year ago?; (3) Are there any instances where your memory poses challenges during the execution of important tasks?; (4) Are individuals around you aware of the decline in your memory?; and (5) Do you consider yourself less adept at performing daily tasks that you were once proficient at?Each question permits self-assessment through three potential responses: "no," "occasionally yes," or "frequently yes," corresponding to scores of 0, 1, and 2, respectively.The cumulative scores of KDSQ-P range from 0 to 10, with higher scores indicating increased levels of SCD.Participants who scored ≥4 were advised to seek further evaluation. 4In this study, participants who scored ≥4 from the KDSQ-P were classified as the SCD group.* Analysis excluding individuals diagnosed with dementia within one year of the index date † Analysis excluding the outliers of TUG and OLS tests a Prescription of donepezil, galantamine, rivastigmine, or memantine with ICD-10 code F00, G30 b Prescription of donepezil, galantamine, rivastigmine, or memantine with ICD-10 code F01 Abbreviations: TUG, timed-up-and-go; OLS, one-leg-standing; SCD, subjective cognitive decline; MCR, motoric cognitive risk; HR, hazard ratio; CI, confidence interval; AD, Alzheimer's disease; VD, vascular dementia

eTable 1. Sex-and test condition-specific mean, standard deviation, and cut- off values of TUG and OLS test
* Time (s) of the original data were reported in whole numbers.Abbreviations: TUG, timed-up-and-go; OLS, one-leg-standing; M, mean; SD, standard deviation eTable 2.

Descriptive characteristics and standardized mean differences for the original and propensity score-matching cohorts: MCR-TUG Participants, No. (%)
SI conversion factors:To convert hemoglobin to g/L, multiply by 10.0; HDL to mmol/L, multiply by 0.0259; LDL to mmol/L, multiply by 0.0259; triglycerides to mmol/L, multiply by 0.0113.eTable 3.
a Adjusted for sex and income b Adjusted for sex, income, and lifestyle factors (physical activities, smoking, and alcohol consumption) c d

eTable 5. Propensity score matching data analysis: risk of incident dementia according to Impaired TUG, Impaired OLS, SCD, and MCR
Analysis excluding individuals diagnosed with dementia within one year of the index date † Analysis excluding the outliers of TUG and OLS tests a Prescription of donepezil, galantamine, rivastigmine, or memantine with ICD-10 code F00, G30 b Prescription of donepezil, galantamine, rivastigmine, or memantine with ICD-10 code F01 *